Most cars today have disc brakes on at least the front two wheels of the vehicle. Many cars have disc brakes on all four wheels. The brake disc or rotor is usually made of cast iron or a ceramic based material. The brake disc has brake pads mounted on a caliper that are forced on to the rotor where friction causes the wheel to stop turning. The brake pads can be powered by a variety of different means. For example, the brake pads can be powered mechanically or hydraulically. The pads can also be powered pneumatically or electromagnetically.
The brake caliper is an assembly that houses the brake pads and pistons. There are fixed calipers that do not move relative to the disk. The fixed caliper uses one or more pairs of opposing pistons to clamp from each side of the disk. This type of caliper is more complex than the floating caliper. A floating caliper also known as a sliding caliper with respect to the disk. The caliper moves along a line that is parallel to the axis of rotation of the disk. A piston on one side of the disk pushes the inner brake pad until it makes contact with the braking surface. Then the piston pulls the caliper body with the outer brake pad so pressure is applied to both sides of the disk.
The caliper typically has a housing that is made from metal or other suitable material. Many of the vehicles today have alloy wheels. These alloy wheels are usually fairly open to reduce the weight of the wheels and to permit air to cool the brake pads. Because of the open nature of many of today's wheels, there is a greater likelihood the caliper can be seen through the wheels. In addition, because the caliper is open to the air there is a risk of corrosion on the caliper from moisture and road salt.
In order to protect the caliper from the elements and reduce the amount of corrosion, it is sometimes desirable to protect the surface of the caliper with a protective coating. The protective coating can be a paint based product or other material. The paint or other protective material must be able to withstand the high temperatures that are generated by the calipers during use. Thus, a high temperature paint is preferable; one such paint is high temperature engine paint.
Painting the calipers is a time consuming process. First, the car should be jacked up and the tires and rims are removed. The entire car should be covered including the wheel well. A drape or newspapers and tape are preferable. The caliper should be cleaned with a wire brush and a cleaning solution. The better the caliper is cleaned the better the paint will stick. The caliper should be removed using the bolts on the back side of the caliper. Once the caliper is removed it should be cleaned again with brake cleaner and a tooth brush. All exposed cylinders should be masked. The caliper should be positioned so that all sides can be accessed and then thoroughly spray painted. The paint should be allowed to dry and then additional coats should be applied with suitable drying between each coat.
It will be appreciated that the traditional manner of painting brake calipers is fairly time consuming, and unless great care is taken in cleaning the caliper, there is a high risk that the paint will not adhere. In addition to being time consuming, it can be difficult for anyone but an experienced mechanic to remove the caliper in a simple and expeditious manner.